Process for cleaning iron ores.



E. F. GOLTRA. PROCESS FOR CLEANING IRON ORES.

'APPLIOATION FILED 001218, 1909.

961,121 Patented June 14,1910

IIIIII I 1 r1 b l nnwA-Rn F. comm, or sr. LOUIS-,7 MISSOURI.

PROCESS FOR CLEANING IRON ORES/ To all whom alt-may concern: I Be itknown that I, Eowsno F. Gowns, a

citizen of the United; States,andresidentof St. Louis, in the State ofMissouri, have invented certain new. and useful .Imprm'ementsin-Processes for- Gleaning Iron Ores,

of which the following is a specification. I

This invention relates to a process for cleaning iron ores-and; forpreparing the same for the subsequent operations.

Some iron ores, as brown hemat1te, contain' a large percentage of clayand sometimes silicaas a angue, and thisgangue must be separated fromthe ore before it-can be used in a blast furnace.

In my co-pending application, Serial No. 536,403, filed January4:,"1910', a process is described whereby iron ore is cleaned of itsgangue by a; blast.

The objects of this invention are to refine the process broadlydescribed and claimed in the above application so as torender itcontinuous.

This invention generally stated consists in the operations ashereinafter fully described The apparatus preferably consists of arunwa-y'upon which the ore is thrown. The oreon the runway is subjectedto a strong blast so as to dry the gangue and render the earthy, thesilicious and any other gangue.

easily separablesfrom: the ore. The ore is tumbled to shake'loosethegangue from the ore, and the gangue is removed by'the blast.

The runway is preferably in the form of along incl'inedtube or drum,which is rotated about its longitudinal axis, and a hop er 'is locatedat one'end of the drum for disc arging the ore into the same. The ore inits passage downwardly is heated to dry out the ore and render theganguebrittle and easily separable from the ore, and the rotation of thedrum will tumble and rattle the ore as it dries and. cause the gangue tobe shaken loose from the ore and pulverized by "the tumbling action.The'strong blast sweeps,

cleans and washes the gangue from the ore and this gangue is withdrawnfrom the drum by the blast fwhile the cleaned ore passes along the drumto the discharge end.

The ore as mined must be dried slowly especially if-it contains muchclay as a gangue since a rapid heating would cause this clay to be bakedhard and burned to a brick and thus it 'would'be impossible or exfSpecification of Letters Patent.

Qkppiication filed October 18, 1909. Serial No. 523,091.

lining 22..

Patented June 14, 1910.

ceedingly diflicult to thereafter loosen it from the ore. For thispurpose the hot blast enters the drum at the lower end, that is at thedischarge end, and when it strikes the fresh ore admitted from thehopper this hot blast is cooled down enough so that its temperature is.sufliciently low to prevent the hard baking and burning of the gangue.

In the drawing the figure is a view showing one form of apparatuswhereby the proc:

ess may be carried out. Referring to the'drawing, 10 designates a runwayin the form of a t-ube or drum provided with a number of rin s 11,11,-resting on .a number of sets of anti-friction rollers suitableframe-work, and the hopper 15 on head 13 discharges into the drum. Asuction fan 16-is connected to the head 14 and is driven bya suitablemotorrso as to create a strong blast inand through the drum 1(). Aburner 17 extends through the head 13 so as l to heat the blast. Thisburner may be an ord'inary oil burner provided with an air blast.

The head 13 is further provided withan air hole 21,- or. air holes, soas-to allow theblast to enter nearthe burner and be heated there by, Thehead is further provided with a discharge or; outlet 18- for the cleanedore. The drum is inclined from the inlet tothe discharge end and isrotated by a drivingpinion 19 engaging a gear 20 on the drum. The drumis lined with a 'Theore as mined} is crushed so as to resuitablerefractory Y 12, 12. The ends of the drum extend into stati'onary heads13, 14 which are bolted to a duce it'to'w'orka-ble form. It is notnecessary to pulverizeit, but it is'sufficient if it can pass through atwo ortwo and one-half 5 inch mesh, This crushed ore is placed in the.hopper 15 and is discharged into the drum 10; The burner 17 furnishesthe necgreatest at the lower end of the drum, but at the upper end thistemperature will be considerably reduced, so that the fresh wet ore willnot be heated to a-suflici'ent degree so as to hard bake the gangue. Asthe ore moves downwardly it will be tumbled and thrown around so astoknock loose allof the gangue which clings ,toit, this gangue becomingmore and more heated and more and more loose, dried and pulverized as itproceeds to--' ward the lower end of the drum. Theore is cleaned andwashed of its gangue by the" essa'ry heat and the temperature will bethe v blast passing through the drum, the gangue being drawn off by thestrong blast which is created by the suction fan 16. The drum 'is madelong enough and the speed of rotation is governed so that at the timewhen the ore reaches the discharge 18 practically all of be subjected tothe high temperature as would be the case if the burner 17 were placedat the upper end of the drum.

In the form of the invention shown in the .figure the heat is generatedby a burner 17.

It is, however, advantageous in some instances to generate this heat bypassing a hot blast directly through the aperture 21 in the head 13,.and into the lower end of the drum I 10. It is also obvious that the oremay be heated in any other suitable manner, therefore, it is tobe-understoodthat this invention is not to be limited to the specificmeans for heating the ore. Where a hot blast is directly used forfurnishing the heat the fan 16 may be dispensed with if desired.

It will be noted that the blast'is passed through and above-the orewhile it is agitated. The rotation of the drum will cause the ore torise with the sides of the drum and fall through the blast passingthrough the drum. In this way the strong blast sweeps. the pulverizedgangue clin ing to and surrounding the ore with it, a lowing the cleanedore to pass down the drum to the discharge 18. The blast seeks out thegangue in the crevices and around the ore and carries it away with it.It will be remembered that the pieces of ore are comparatively large andheavy and therefore in their tumbling motion ractically all the gan ewill be knocked o and pulverized.

T e length of the'drum, its diameter, its incline, the speed of rotationand the temperatures will vary with difierent ores and with theircondition as to dampness, the amount of clay in them, etc. As apractical case, where an oil burner is used the temperature at the lowerend of the drumwill be 2000 F. orvove'r, while the temperature at theupper end will be 300 to 400 F. Inallcases however, the process is soregulated'that the gangue will be dried and ren dered. separable, shakenloose,'and separated, the temperatures being controlled so that thegangue will be thoroughly dried and still dried gradually enough" sothat it will not become hard baked. Another important result obtained isthat the moisture in the ore is driven oli: during thisprocess, leavingthe cleaned ore in a dry porous condition. Thus :tumbling the ore .andits the amount of heat necessary in the other operations is materiallyreduced.

It is obvious that various changes may be made without departing fromthis invention, and it is therefore to be understood that thisinventionis not to be limited to c the specific arrangements scribed.

The broad process is broadly claimed in my co-pending application SerialNo. 536,403, referred to.

Having thus described the invention, what is claimed'is: V

1. The-herein described process of treat-f ing iron ores containingmoist clay, etc., as

shown and de'- a gangue, which consists in heating the ore and itsgangue at a temperature and for a" period sufficient to drive ofli' themoisture and to render the angue easily separable from the ore, tum lingthe ore and its gangue during the heating operation to shake loose thegangue from the ore, and'to pulverize the gangue by saidtumblinga'ction, and subjecting the ore and its gangue during theheating and tumbling operation to a strong gaseous blast which sweeps,cleans and removes the gangue fromtthe.

ore. V

2. The herein described process of treating iron, ores containing moistclay, etc., as a gangue, which consists in subjecting the ore and gangueto'a strong hot gaseous blast at a temperature and for a periodsufficient to drive oil the moisture and render the gangue easilyseparable from the ore, tumbling-theoreand its gangue during the heatingoperation .to shake loose the gangue from the ore and to pulverize thegangue by said tumbling action, and sweeping, cleaning, and removing thegangue from the ore by said blast during the heating and turn blingoperation, the blast being applied to strike the drier. portions of theore and gangue before the damper portions to gradually heat; the gangue.

3. The herein described process of treat- .ing-iron ores containingmoist clay, etc., as

acgangue, which consistsin passing the ore and its gangue along arunway, passlng a strong hot gaseous blast along said runway from thedischarge to the admission end so 7 as to gradually heat and'dry thegangue and render it easily separable from the ore, gangue in theirpassage along the runway to shake 'loose the ganguefrom the ore, and topulverize the gangue by said tumbling action, and sweeping, cleaning,and removing the gangue from the ore by said blast.

Intestimony whereof I aflix my signature in presence of two witnesses. Ka

EDWARD F. GOLTRA. Witnesses:

J. H. BRUNINGA, WALTER E. PAUL.

